Metaconfig unit change for 10624.

[p5sagit/p5-mst-13.2.git] / hv.h

diff --git a/hv.h b/hv.h
index f8cf2b9..a9fc9fb 100644 (file)
--- a/hv.h
+++ b/hv.h
@@ -1,6 +1,6 @@
 /*    hv.h
  *
- *    Copyright (c) 1991-2000, Larry Wall
+ *    Copyright (c) 1991-2001, Larry Wall
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -43,14 +43,22 @@ struct xpvhv {
 };
 
 /* hash a key */
+/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins */
+/* from requirements by Colin Plumb. */
+/* (http://burtleburtle.net/bob/hash/doobs.html) */
 #define PERL_HASH(hash,str,len) \
      STMT_START        { \
        register const char *s_PeRlHaSh = str; \
        register I32 i_PeRlHaSh = len; \
        register U32 hash_PeRlHaSh = 0; \
-       while (i_PeRlHaSh--) \
-           hash_PeRlHaSh = hash_PeRlHaSh * 33 + *s_PeRlHaSh++; \
-       (hash) = hash_PeRlHaSh + (hash_PeRlHaSh>>5); \
+       while (i_PeRlHaSh--) { \
+           hash_PeRlHaSh += *s_PeRlHaSh++; \
+           hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
+           hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
+       } \
+       hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
+       hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
+       (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
     } STMT_END
 
 /*